A little bit about HTTPS and TLS 1.2 (bulatov.me)

I was curious about how TLS works in detail, so I wrote an article in which I discussed TLS 1.2 with the AES-CBC cipher. Although this cipher is weak and TLS 1.2 isn't the newest standard, I aimed to demystify TLS for myself—from seeming like magic to being implementable in 300 lines of Python. I would appreciate any feedback.